Studies on Stress and Strain State in Cold Orbital Forging a AlMgSi Alloy Flange Pin

2013 ◽  
Vol 58 (4) ◽  
pp. 1183-1189 ◽  
Author(s):  
G. Samołyk

Abstract The orbital forging is one of the metal forming processes which enables the manufacture of products through worm or cold working. A characteristic feature of this technological process is the use of a special wobbling motion of one of the tools in order to reduce the required forming force. This is particularly advantageous during the formation of products in the shape of a disc or a flange pin. Unfortunately, typical constraints of cold orbital forging are: uncontrolled buckling, loss of shape stability (“mushroom effect”) and cracks. They depend on the technological parameters of the process and their cause can be explained on the basis of e.g. workpiece stress state analysis, which is a difficult task due to the complexity of orbital forging process. The article discusses the issues of stress and strain in cold orbital forged parts of the flange pin type, made of AlMgSi aluminum alloy. The results of the presented FEM simulation, verified experimentally, explain the influence of the theoretical aspects of this process on its implementation conditions. It is assumed that orbital forging is performed on the PXW-100A press and the numerical model takes into account all possible variants of the process. Debate boils down to discussing the stress and strain state (e.g. analyzing the stress and strain rate fields) occurring in the workpiece in the context of chosen technological parameters and constrains of orbital forging process

2014 ◽  
Vol 622-623 ◽  
pp. 1228-1234
Author(s):  
Grzegorz Samołyk

The paper presents selected results of a numerical investigation of the orbital forging process for producing a hollow part. This part is a jaw coupling sleeve made of titanium alloy, widely used in the agricultural industry. The FEM simulation was performed based on the following assumptions: (i) the orbital forging process is conducted under hot conditions using an industrial press of MCOF type and (ii) the final part is formed from a special hollow preform. The preform shape was selected such to ensure optimal conditions of the orbital forging process. The aim of the investigation was to identify phenomena which occur during the orbital forging process. The results obtained are thoroughly examined and described.


Author(s):  
V Alimirzaloo ◽  
S SheydayiGurchinQaleh ◽  
P MashhadiKeshtiban ◽  
S Ahmadi

Lubrication is an essential factor in the metal forming processes such as forging, since it leads to reducing friction at contact surfaces and increasing the surface quality of the forged parts. In order to create desirable tribological properties in the base lubricants, various metal oxide nanoparticles are mostly used as additives. In the present study, the effects of the nanolubricants made by copper oxide (CuO) and alumina (AL2O3) nanoparticles on the surface quality of the forging process have been investigated. The effects of the nanolubricants have been compared with the graphite as a conventional lubricant. Upsetting forging operation of a ring shape workpiece was used for evaluating the lubricants. Experiments were designed and analyzed using Taguchi method and analysis of variance. Results show that the nanolubricants cause a significant improvement on the surface roughness compared to conventional lubricants. Best condition is obtained when 0.8 wt% of CuO nanoparticles is added in paraffin lubricant. Compared with the case of base lubricants with no additives, roughness reduced by 41% and 33% for paraffin and oil10, respectively. Also, the surface roughness decreased by 496% and 235% compared with dry graphite powder and paraffin with 25% graphite, correspondingly.


Author(s):  
Nikolay A. Makhutov ◽  
◽  
Dmitry A. Neganov ◽  
Eugeny P. Studenov ◽  
◽  
...  

In the factory, pipes for trunk oil and oil product pipelines are obtained by molding and welding. To ensure a cylindrical shape and reduce technological residual stresses, expansion technology is used. Pipe expansion causes a significant change in the values of residual deformations and stresses. The article presents both the calculation results and graphs regarding stress and strain distribution during bending of the stock and their redistribution after expansion. Based on the calculation results, the final total values of residual stresses and residual deformations caused by bending and expansion were stated to be important components of the stress-strain state observed in pipelines being operated under cyclic loading, as well as those used in assessing how degradation affects the ductility of the pipe material. These factors were concluded as being reasonably taken into account when performing verification calculations regarding long-running pipelines if, based on their diagnostics and analysis, their state does not meet modern strength requirements.


1993 ◽  
Vol 317 ◽  
Author(s):  
R.M. Osgood ◽  
B.M. Clemens ◽  
R.L. White ◽  
S. Brennan

ABSTRACTGrazing incidence and asymmetric X-ray diffraction were used to measure the stress and strain state of Fe(110)/Mo(110) Multilayers. The highest stress in the Fe constituent of the multilayer was along the [110] in-plane direction and was due to interaction with the substrate. The Magnetic anisotropy of the Fe Multilayer constituent was measured and the magnetic surface anisotropy, which favored in-plane [001] magnetization, was deduced. In contrast, the magnetic surface anisotropy of a single layer of Fe on W preferred in-plane [110] magnetization, in agreement with the Néel Model.


2021 ◽  
Vol 901 ◽  
pp. 176-181
Author(s):  
Tung Sheng Yang ◽  
Chieh Chang ◽  
Ting Fu Zhang

This paper used finite element analysis of metal forming to study the forging process and die design of aluminum alloy brake parts. According to the process parameters and die design, the brake parts were forged by experiment. First, the die design is based on the product size and considering parting line, draft angle, forging tolerance, shrinkage and scrap. Secondly, the finite element analysis of metal forming is used to simulate the forging process of aluminum alloy brake parts. Finally, the aluminum alloy brake levers with dimensional accuracy and surface hardness were forged.


2021 ◽  
Vol 70 (1) ◽  
pp. 43-61
Author(s):  
Arkadiusz Popławski

This paper presents the results of an experimental and numerical study of the perforation of Armox 500T armoured steel. The plate perforation was performed with a pneumatic gun using three types of penetrators. Sharp, spherical and blunt penetrators were used. The use of different geometries of penetrators causes the process of perforation and destruction of plates in a different state of stress and strain, which leads to the appearance of three basic modes of failure. Numerical analyses of the perforation process have been carried out using the Ls-Dyna computational code with an advanced constitutive model of the material and the integrated failure model. The obtained experimental and numerical results were analysed and compared. The failure shape, the level of plastic deformation and the parameters of stress and strain state were analysed.


2017 ◽  
Vol 139 (12) ◽  
Author(s):  
Yuanchao Li ◽  
Huang Chen ◽  
Joseph Katz

Modeling of turbulent flows in axial turbomachines is challenging due to the high spatial and temporal variability in the distribution of the strain rate components, especially in the tip region of rotor blades. High-resolution stereo-particle image velocimetry (SPIV) measurements performed in a refractive index-matched facility in a series of closely spaced planes provide a comprehensive database for determining all the terms in the Reynolds stress and strain rate tensors. Results are also used for calculating the turbulent kinetic energy (TKE) production rate and transport terms by mean flow and turbulence. They elucidate some but not all of the observed phenomena, such as the high anisotropy, high turbulence levels in the vicinity of the tip leakage vortex (TLV) center, and in the shear layer connecting it to the blade suction side (SS) tip corner. The applicability of popular Reynolds stress models based on eddy viscosity is also evaluated by calculating it from the ratio between stress and strain rate components. Results vary substantially, depending on which components are involved, ranging from very large positive to negative values. In some areas, e.g., in the tip gap and around the TLV, the local stresses and strain rates do not appear to be correlated at all. In terms of effect on the mean flow, for most of the tip region, the mean advection terms are much higher than the Reynolds stress spatial gradients, i.e., the flow dynamics is dominated by pressure-driven transport. However, they are of similar magnitude in the shear layer, where modeling would be particularly challenging.


Sign in / Sign up

Export Citation Format

Share Document